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| author | Nikita Popov <npopov@redhat.com> | 2022-10-20 12:28:31 +0200 |
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| committer | Nikita Popov <npopov@redhat.com> | 2022-10-20 12:47:17 +0200 |
| commit | 783301298f1e151b82c1be21bc6a214b9ef525bd (patch) | |
| tree | 8735a552bd8376607e0d763d1d78b36ba77a8908 /compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp | |
| parent | 4b3b731b55a588dd34a75bbb87fdaaec2e3f5707 (diff) | |
| download | rust-783301298f1e151b82c1be21bc6a214b9ef525bd.tar.gz rust-783301298f1e151b82c1be21bc6a214b9ef525bd.zip | |
Don't use usub.with.overflow intrinsic
The canonical form of a usub.with.overflow check in LLVM are separate sub + icmp instructions, rather than a usub.with.overflow intrinsic. Using usub.with.overflow will generally result in worse optimization potential. The backend will attempt to form usub.with.overflow when it comes to actual instruction selection. This is not fully reliable, but I believe this is a better tradeoff than using the intrinsic in IR. Fixes #103285.
Diffstat (limited to 'compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp')
0 files changed, 0 insertions, 0 deletions